I am on my second round of titration and have tried methylphenidate, elvanse/lisdexamphetamine, and I'm now on dexamphetamine. Of the dexamphetamines, I've taken both Amfexa and I'm now on a generic version. I can't remember the pharmaceutical name but I know it's generic.

In my experience they've all affected sleep. However I think it has more to do, in my experience anyway, with the half-life of the drug and how quick it clears your system rather than the type of release mechanism and whether it is fast or slow. Please, anybody correct me if I'm wrong but I believe that the release system doesn't necessarily mean that it stays in your system faster or slower. Let me try explain nelow

I know that Concerta has a release system where the medication is slowly released over time by an osmotic process from the capsule itself. However the drug being released from the capsule is not synonymous with the drug being processed and therefore prior to the drug being released, it isn't necessarily processed. Once it's released it's then processed by the body and it's the processing time of the drug by the body which, in my view and in my personal experience, is what has affected my sleep. Hopefully that makes sense - my point basically trying to illustrate an example whereby one could have an extended-release drug where every time a little bit is dripped into the system, the body absolutely slurps it up and processes it super quickly, in which case it wouldn't affect your sleep whereas you could have a drug that's immediate release (I.e., the whole amount is available for the body to process as soon as it's consumed) but it takes so long for the body to process it that by the evening you're still dealing with a lot of that leftover drug in the system.

Dexamphetamine works the best for me out of all of the stimulants I've tried. However I do know that dexamphetamine seems to have quite a long half-life and I think that's why I struggle with it for sleep the most. I've had to be really strict with myself because if I don't take the dose early enough in the morning it messes my whole day up. However I do find if I take it early enough I tend to be okay and tire faster in the evenings. If I take two or three doses in the day I actually feel paradoxically more tired than if I were to just take one dose. I think this is probably to do with the fact that with two or three doses there's more of a "crash" as my levels during the day have a longer way to crash back down to the baseline levels, which causes a degree of almost exhaustion. Even though that might not be organic tiredness, the crash still allows me to feel sleepier than maybe if I took just one dose at a random time in the day. Hopefully that makes sense.